Method and apparatus for percutaneously securing a bone screw and a bone plate to a bone of a patient

ABSTRACT

A method of percutaneously implanting a first component and a second component of an orthopaedic assembly into a body of a patient includes the steps of securing a first instrument to the first component, and advancing the first component into the body of the patient. The first instrument is advanced into the body of the patient such that a portion of the first instrument extends out of the body. A second instrument is secured to the second component, and the second component is advanced into the body of the patient. The second instrument is advanced into the body of the patient such that a portion of the second instrument extends out of the body. A third instrument is advanced into contact with both the first instrument and the second instrument so as to position the first component and the second component in a predetermined position relative to one another. An instrument assembly for percutaneously implanting an orthopaedic assembly is also disclosed.

CROSS REFERENCE

This patent application is a divisional of copending U.S. patentapplication Ser. No. 11/083,195, filed Mar. 17, 2005 which is adivisional of U.S. patent application Ser. No. 09/934,052, now issued asU.S. Pat. No. 6,916,323, the disclosures of each of which are herebyincorporated by reference.

FIELD OF THE INVENTION

The present invention relates generally to implantable bone screws andbone plates, and more particularly to a method and apparatus forpercutaneously securing a bone screw and a bone plate to a bone of apatient.

BACKGROUND OF THE INVENTION

Minimally invasive surgical techniques have been developed for manydifferent types of surgical procedures. Such techniques attempt tobalance the need to achieve the goal of the surgical procedure whileminimizing the surgical injury to the patient. As such, surgeriesperformed by use of minimally invasive techniques generally result inlower postoperative morbidity, shorter postoperative hospital stay, lesspostoperative pain, decreased cost, and quicker recovery as compared to“open” or conventional surgical techniques. Because of theaforementioned advantages, these minimally invasive techniques are beingapplied to an increasing variety of surgical procedures. For example,minimally invasive techniques in the form of laparoscopic procedures,such as a laparoscopic colectomy for carcinoma of the colon, have beendeveloped.

However, despite growing use in other surgical fields, minimallyinvasive techniques have not been significantly developed for use inorthopaedic procedures. In particular, although orthopaedic surgeonshave recognized the general principle that maintenance of soft tissuecontributes significantly to the post operative healing process,conventional techniques in which the soft tissue is completely opened togain complete access to the bone structure thereunder are still in widespread use. One reason for this is the unique nature of many orthopaedicprocedures. In particular, orthopaedic procedures often involve the“delivery” (i.e., implantation) of devices which are relatively large indesign compared to the “deliverables” associated with other forms ofsurgery. Specifically, in the case of, for example, an appendectomy,minimally invasive techniques are readily adaptable since the surgeonmay aptly remove the subject tissue (i.e., the patient's appendix) andthereafter deliver and install the necessary sutures through therelatively small confines of a cannula of a trocar. However, in the caseof, for example, trauma repair of a heavily fractured long bone (e.g., afemur or tibia), a number of relatively large plates are screwed orotherwise fastened to the fracture bone. The size of such plates haslong since been viewed as prohibiting in regard to the use of minimallyinvasive techniques for the implantation of such components.

As such, orthopaedic surgeons have typically preferred to open the softtissue surrounding the bone to be treated in order to completely exposethe surgical site thereby providing for ease of plate delivery. As aresult of such continued use of “open” procedures, soft tissuesurrounding the bone continues to be compromised thereby impairingnormal blood circulation to the treated bone, potentially delayingfracture healing, and potentially increasing the risk of infection.Indeed, although the majority of patients treated with such proceduresheal without complication, there are certain occasions in whichcomplications such as infection or refracture occur thereby prolonginghealing rates and, in certain cases, increasing the rates of secondaryrevisions. As a result of the aforedescribed shortcomings associatedwith traditional orthopaedic surgeries, along with the promiseassociated with minimally invasive techniques, a number of attempts havebeen made to provide certain of the advantages associated with minimallyinvasive techniques to certain orthopaedic procedures. For example,plate fixation assemblies have heretofore been developed for use infracture repair of femurs. However, such assemblies suffer from a numberof drawbacks. For example, such assemblies suffer from a certain degreeof inflexibility in regard to the manner in which the orthopaediccomponent is implanted. For instance, the prosthesis utilized with suchassemblies must generally be “pre-assembled” prior to implantationthereof. Specifically, since it is difficult, if not impossible, for thesurgeon to visualize the implanted prosthesis, in vivo assembly of theprosthesis is rendered equally difficult, if not impossible.

What is needed therefore is an apparatus and method for use in theperformance of minimally invasive orthopaedic procedures which overcomeone or more of the above-mentioned drawbacks.

SUMMARY OF THE DISCLOSURE

The present invention provides for percutaneous implantation oforthopaedic assemblies thereby eliminating the need to utilizerelatively elongated incisions. The concepts of the present inventionare particularly useful in regard to the implantation and installationof bone plates to the long bones of the human skeletal system such asthe femur. In practice, the concepts of the present invention allow forimplantation of a hip screw and bone plate through a relatively smallincision (e.g., 2-3 centimeters). Once implanted, the hip screw and boneplate may be aligned and engaged with one another by use of theapparatus and techniques described herein. By utilizing such a smallincision relative to heretofore utilized techniques (e.g., “open”incisions), the concepts of the present invention reduce the number ofoccurrences of postoperative complications such as infection,refracture, or prolonged healing rates.

In accordance with one illustrative embodiment of the present invention,there is provided a method of percutaneously implanting a firstcomponent and a second component of an orthopaedic assembly into a bodyof a patient. The method includes the steps of securing a firstinstrument to the first component, and advancing the first componentinto the body of the patient. The first instrument is advanced into thebody of the patient such that a portion of the first instrument extendsout of the body. A second instrument is secured to the second component,and the second component is advanced into the body of the patient. Thesecond instrument is advanced into the body of the patient such that aportion of the second instrument extends out of the body. A thirdinstrument is advanced into contact with both the first instrument andthe second instrument so as to position the first component and thesecond component in a predetermined position relative to one another.

In accordance with another illustrative embodiment of the presentinvention, there is provided an instrument assembly for percutaneouslyimplanting an orthopaedic assembly. The instrument assembly includes afirst instrument which is adapted to be secured to a first orthopaediccomponent. The first instrument has a first alignment feature. Theinstrument assembly also includes a second instrument which is adaptedto be secured to a second orthopaedic component. The second instrumenthas a second alignment feature. The instrument assembly further includesa third instrument having a third alignment feature which is adapted tocooperate with the first alignment feature and the second alignmentfeature so as to position the first instrument and the second instrumentin a predetermined position relative to one another.

In accordance with another illustrative embodiment of the presentinvention, there is provided a method of percutaneously securing a boneplate to a bone within a body of a patient. The method includes the stepof securing a screw locating instrument to a bone screw. The bone screwis screwed into the bone of the patient. The screw locating instrumentis advanced into the body of the patient such that a portion of thescrew locating instrument extends out of the body. In addition, a platelocating instrument is secured to the bone plate, and the bone plate isadvanced into the body of the patient. The plate locating instrument isadvanced into the body of the patient such that a portion of the platelocating instrument extends out of the body. An alignment instrument isadvanced into contact with both the screw locating instrument and theplate locating instrument so as to position the bone screw and the boneplate in a predetermined position relative to one another.

In a specific exemplary embodiment for use in a hip repair procedure,there is provided an instrument assembly for percutaneously implanting ahip screw and a bone plate. The instrument assembly includes a screwlocating instrument which is adapted to be secured to the hip screw. Thescrew locating instrument has a first alignment feature. The instrumentassembly also includes a plate locating instrument which is adapted tobe secured to the bone plate. The plate locating instrument has a secondalignment feature. An alignment instrument has a third alignment featurewhich is adapted to cooperate with the first alignment feature and thesecond alignment feature so as to position the screw locating instrumentand the plate locating instrument in a predetermined position relativeto one another thereby positioning the hip screw and the bone platerelative to one another.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a bone screw locating instrument;

FIG. 2 is a cross sectional view taken along the line 2-2 of FIG. 1, asviewed in the direction of the arrows, note that the knob and a portionof the rod are not shown in cross section for clarity of description;

FIG. 3 is a perspective view of a bone plate locating instrument;

FIG. 4 is a cross sectional view taken along the line 4-4 of FIG. 3, asviewed in the direction of the arrows;

FIG. 5 is a perspective view of an alignment instrument;

FIGS. 6 and 7 are perspective views of a screw targeting instrument;

FIG. 8 is a partial cutaway perspective view of a bone lag screwassembly;

FIG. 9 is a perspective view of a bone plate;

FIG. 10 is a bottom elevational view of the bone plate of FIG. 9;

FIG. 11 is a cross sectional view taken along the line 11-11 of FIG. 9,as viewed in the direction of the arrows;

FIGS. 12-18 are diagrammatic perspective views which show a patient'sfemur during various steps of a procedure for percutaneously implantingthe components of FIGS. 8-11;

FIG. 19 is an elevational view of a screw sleeve;

FIG. 20 is an enlarged fragmentary perspective view of a portion of FIG.19 which is encircled and indicated as FIG. 20;

FIG. 21 is an elevational view of a drill guide;

FIG. 22 is an elevational view of a trocar; and

FIG. 23 is an elevational view of a bone drill.

DETAILED DESCRIPTION OF AN ILLUSTRATIVE EMBODIMENT

While the invention is susceptible to various modifications andalternative forms, specific exemplary embodiments thereof have beenshown by way of example in the drawings and will herein be described indetail. It should be understood, however, that there is no intent tolimit the invention to the particular forms disclosed, but on thecontrary, the intention is to cover all modifications, equivalents, andalternatives falling within the spirit and scope of the invention asdefined by the appended claims.

Referring now to FIGS. 1-7, there is shown an instrument assembly 10which may be utilized to percutaneously implant a surgical device into abody of a patient. As will be discussed below in greater detail, use ofthe instrument assembly 10, along with the associated techniques, allowsfor the implantation of such a device through a relatively smallincision thereby providing numerous advantages associated with minimallyinvasive surgical techniques including a reduction in the number ofpostoperative complications such as infection, refracture, or prolongedhealing rates. One particularly useful implementation of the concepts ofthe present invention relates to the percutaneous implantation of a boneplate 12 (see FIGS. 9-11) during treatment of a fractured long bone suchas a femur 200 (see FIGS. 12-18). As such, the concepts of the presentinvention will herein be described in regard to the percutaneousimplantation and securement of the femoral bone plate 12; however, itshould be appreciated that such a description is exemplary in nature andthat other applications of the concepts of the present invention arecontemplated.

The instrument assembly 10 includes a screw locating instrument 14 (seeFIGS. 1 and 2), a plate locating instrument 16 (see FIGS. 3 and 4), analignment instrument 18 (see FIG. 5), and a screw targeting instrument20 (see FIGS. 6 and 7). The screw locating instrument 14 is utilized tomaintain a bone screw such as a hip lag screw assembly 22 (see FIG. 8)in a desired orientation subsequent to implantation thereof. In oneexemplary embodiment, the lag screw assembly 22 includes an outer barrel24 with a screw 26 captured therein. The screw 26 includes a shaft 28having a number of threads 30 on one end thereof and a head 32 on itsother end.

The configuration of the threads 30 and the head 32 of the screw 26prevent the screw 26 from becoming separated from the barrel 24. Inparticular, as shown in FIG. 8, the shaft 28 of the screw 26 extends outof a hole 34 defined in one end of the barrel 24. The head 32 of thescrew 26 has a diameter which is larger than the diameter of the hole 34thereby preventing the head 32 from being advanced in a first directionthrough the hole 34 and hence out of the barrel 24. Similarly, thediameter of the threads 30 is likewise greater than the diameter of thehole 34 thereby preventing the screw 26 from being advanced through thehole 34 and hence into (and thereafter out of) the barrel 24 in theopposite direction.

The barrel 24 of the lag screw assembly 22 has a flange 36 securedthereto. As shown in FIG. 8, the flange 36 is secured to the end of thebarrel 24 opposite of the hole 34. The flange 36 is non-rotatablysecured to the barrel 24 by way of being integrally formed therewith orby use of securement techniques such as welding. As shall be discussedbelow in greater detail, the flange 36 cooperates with features definedin the bone plate 12 in order to secure the two components to oneanother.

As shown in FIGS. 9-11, the bone plate 12 has an elongated body 38having a slot 40 and a number of holes 42 defined therein. As will bediscussed below in greater detail, the hip lag screw assembly 22 ispositionable so as to be accessible through the slot 40, whereas anumber of bone screws 212 (see FIG. 18) may be advanced through theholes 42 and thereafter secured to the femur 200. It should beappreciated that although the bone plate 12 is herein described andshown in the drawings as having four holes 42, any number of holes 42may be defined in the plate 12 in order to allow the plate 12 to conformto a particular femoral anatomy or to allow for repair of any type offemoral fracture.

As shown in FIG. 10, a first end of the body 38 of the bone plate 12 hasa rounded or bullet-shaped configuration. Such a shape allows for easeof insertion of the plate through the underlying tissues duringpercutaneous implantation of the plate 12. As shown in FIGS. 9 and 10,the opposite end of the body 38 of the bone plate 12 has a channel 44defined therein. As shown in FIGS. 17 and 18, the flange 36 of the lagscrew assembly 22 may be received into the channel 44 in order to securethe lag screw assembly 22 to the bone plate 12.

As shown in FIGS. 10 and 11, the sidewall of the body 38 at one end ofthe slot 40 has a number of threads 46 defined therein. In an exemplaryembodiment, the threads 46 extend through approximately 180° of thesidewall of the slot 40. As will be discussed below in greater detail,the threads 46 may be engaged by a surgical instrument in order tosecure the bone plate 12 to the instrument during implantation of theplate 12.

As described above, the screw locating instrument 14 is provided tomaintain the lag screw assembly 22 in a desired position and/ororientation during a percutaneous orthopaedic procedure. In order to doso, the screw locating instrument 14 is adapted to be selectivelysecured to the lag screw assembly 22. Specifically, the screw locatinginstrument 14 includes an attachment mechanism 48 having a pair oflocking arms 50. The locking arms 50 have a barb 52 on one end thereofwhich engages the backside of the flange 36 of the lag screw assembly22. The locking arms 50 are pivotally secured to an outer sleeve 54 ofthe instrument 14 by use of a pair of pivot pins 56. A pair of springs58 (see FIG. 2) apply a bias to the end of each of the locking arms 50opposite to the barbs 52 in order to urge the barbs 52 toward oneanother. It should be appreciated that when urged toward one another insuch a manner, the barbs 52 may be utilized to engage the backside ofthe flange 36 of the lag screw assembly 22 thereby securing theinstrument 14 thereto.

The screw locating assembly 14 has an elongated rod 60 which extendsthrough an elongated bore 62 defined in the outer sleeve 54. The rod 60has a knob 64 non-rotatably secured to one end thereof, whereas theother end of the rod 60 has a beveled tip 66 defined therein. A portionof the rod 60 located between the beveled tip 66 and the knob 64 has anumber of threads 68 defined therein. The threads 68 threadingly engagea number of corresponding threads 70 defined in the sidewall of the bore62.

Rotation of the knob 64 in the general direction of arrow 72 of FIG. 1causes similar rotation (i.e., in the direction of arrow 72 of FIG. 1)of the rod 60. Such rotation of the rod 60 causes the threads 68 of therod 60 to threadingly engage the threads 70 of the sleeve 54 in a mannerwhich extends or otherwise urges the beveled tip 66 outwardly in adirection away from the sleeve 54. Such outward movement of the beveledtip 66 causes a cam surface 74 defined in the tip 66 to be spaced apartfrom a cam surface 76 defined in each of the locking arms 50 therebyallowing the springs 58 to urge the locking arms 50 inwardly toward oneanother.

Conversely, rotation of the knob 64 in the opposite direction (i.e, inthe general direction of arrow 78 of FIG. 1) causes similar rotation(i.e., in the direction of arrow 78 of FIG. 1) of the rod 60. Suchrotation of the rod 60 causes the threads 68 of the rod 60 tothreadingly engage the threads 70 of the sleeve 54 in a manner whichretracts or otherwise urges the beveled tip 66 inwardly in a directiontoward the sleeve 54. Such inward movement of the beveled tip 66 causesthe cam surface 74 of the tip 66 to be urged into contact with the camsurfaces 76 of the locking arms 50 thereby overcoming the bias of thesprings 58 so as to urge the locking arms 50 outwardly in a directionaway from one another. In this manner, the barbs 52 of the locking arms50 may be disengaged from the flange 36 of the lag screw assembly 22.

It should be appreciated that in addition to the aforedescribed camfeature, the configuration of the beveled tip 66 facilitates the initialengagement of the screw locating instrument 14 to the lag screw assembly22. In particular, the conically-shaped outer surface 80 of the beveledtip 66 functions as a “spear” for guiding the tip 66 onto an uppersurface 82 defined in the flange 36 of the lag screw assembly 22 (seeFIG. 8) during securement of the screw locating instrument 14 to the lagscrew assembly 22.

As shown in FIGS. 1 and 2, the screw locating instrument 14 may beconfigured to include an alignment feature 84. The alignment feature 84is provided to cooperate with features or mechanisms associated withother instruments such as the plate locating instrument 16 and thealignment instrument 18 in order to position the screw locatinginstrument 14 (and hence the lag screw assembly 22) in a desiredposition and/or orientation.

In one exemplary embodiment, the alignment feature 84 of the screwlocating instrument 14 is embodied as a pair of recesses 86. As will bediscussed below in greater detail, a portion of the alignment instrument18 may be advanced into the recesses 86 of the screw locating instrument14, along with similar recesses defined in the plate locating instrument16, in order to align or otherwise position the instruments 14, 16 in apredetermined position relative to one another.

Referring now to FIGS. 3 and 4, there is shown the plate locatinginstrument 16 in greater detail. The plate locating instrument 16includes a housing 88 having an elongated bore 90 extendingtherethrough. A rod 92 extends through the bore 90. One end of the rod92 has a number of threads 94 defined therein and extends out of a firstend of the housing 88. The housing 88 has a recess 96 defined therein.As shall be discussed below in greater detail, the threaded portion ofthe rod 92 is positionable in the recess 96 during securement of theplate locating instrument 16 to the bone plate 12. The housing 88 of theplate locating instrument 16 has a keying tab 98 extending from the sameend thereof as the threaded portion of the rod 92. The keying tab 98 ispositionable in the slot 40 of the bone plate 12 (see FIGS. 9 and 10) inorder to position the bone plate 12 in a desired orientation relative tothe housing 88 of the plate locating instrument 16.

As shown in FIG. 4, the end of the rod 92 opposite to the threadedportion is press fit or otherwise secured within a bore 100 defined inan inner sleeve 102. Use of the inner sleeve 102 captures the rod 92within the housing 88 of the plate locating instrument 16. Inparticular, the diameter of the threads 94 is larger than the diameterof the bore 90 thereby preventing the threaded portion of the rod 92from being retracted into the housing 88. Moreover, the outer diameterof the inner sleeve 102 is also greater than the diameter of the bore 90thereby preventing advancement of the sleeve 102 (and hence the end ofthe rod 92 secured thereto) through the bore 90 in the oppositedirection.

A knurled knob 104 is slidably secured to the outer surface of the innersleeve 102. A spring 106 biases the knob 104 downwardly in the generaldirection of the threaded end portion 94 of the shaft 92. The springbias exerted on the knob 104 by the spring 106 is utilized to secure thescrew targeting instrument 20 to the plate locating instrument 16. Inparticular, the housing 88 of the plate locating instrument 16 has achannel 108 defined therein (see FIG. 3). An inverted T-shaped flange136 defined in the screw targeting instrument 20 (see FIGS. 6 and 7) ispositionable in the channel 108. As will be discussed below in greaterdetail, the spring 106 biases a lower surface 133 of the knob 104 intocontact with an upper surface 134 of the screw targeting instrument 20when the flange 136 of the instrument 20 is positioned in the channel108 thereby securing the screw targeting instrument 20 to the platepositioning instrument 16.

Similar in nature to the screw locating instrument 14, the platelocating instrument 16 may be configured to include an alignment feature110. The alignment feature 110 is provided to cooperate with features ormechanisms associated with other instruments such as the alignmentfeature 84 of the screw locating instrument 14 and certain featuresassociated with the alignment instrument 18 in order to position theplate locating instrument 16 (and hence the bone plate 12) in a desiredposition and/or orientation.

In one exemplary embodiment, the alignment feature 110 of the platelocating instrument 16 is embodied as a pair of recesses 112. As will bediscussed below in greater detail, a portion of the alignment instrument18 may be advanced into the recesses 112 of the plate locatinginstrument 16, along with the recesses 84 defined in the screw locatinginstrument 14, in order to align or otherwise position the instruments14, 16 in a predetermined position relative to one another.

Referring now to FIG. 5, there is shown the alignment instrument 18 ingreater detail. The alignment instrument 18 is provided to position apair of instruments, and hence the orthopaedic components securedthereto, in a desired position relative to one another. In the exemplaryembodiment described herein, the alignment instrument 18 is utilized toposition the screw locating instrument 14 (and hence the lag screwassembly 22 secured thereto) and the plate locating instrument 16 (andhence the bone plate 12 secured thereto) in a predetermined positionrelative to one another. Specifically, the alignment instrument 18 isconfigured to contact both the screw locating instrument 14 and theplate locating instrument 16 in a manner which causes the twoinstruments 14, 16 to be positioned in a predetermined position relativeto one another thereby positioning the lag screw assembly 22 and thebone plate 12 in a predetermined position relative to one another.

In a more specific exemplary embodiment, the alignment instrument 18 isconfigured to contact both the screw locating instrument 14 and theplate locating instrument 16 in a manner which causes the twoinstruments 14, 16 to be moved in a predetermined manner relative to oneanother such that the flange 36 of the lag screw assembly 22 is advancedinto the channel 44 of the bone plate 12. It should be appreciated thatsuch movement and positioning of the screw locating instrument 14 andthe plate locating instrument 16 allows for in vivo engagement of thebone plate 12 and the lag screw assembly 22 subsequent to implantationthereof.

In order to align a pair of surgical instruments in the manner describedabove, the alignment instrument 18 is configured to include a feature orfeatures which cooperates with features associated with the instrumentsto be aligned. In the exemplary embodiment described herein, thealignment feature of the alignment instrument 18 is embodied as a pairof outwardly extending alignment members 114. In a more specificexemplary embodiment shown in FIG. 5, the alignment instrument 18 isconfigured as a fork-shaped instrument having a handle 116 which issecured to an arcuate-shaped body 118. In this specific exemplaryembodiment, the alignment members 114 are configured as a pair of tines120 which extend outwardly from the body 118. In such a manner, thetines 120 cooperate with the alignment features 84, 110 of the screwlocating instrument 14 and the plate locating instrument 16,respectively. Specifically, the alignment instrument 18 may be advancedinto contact with the screw locating instrument 14 and the platelocating instrument 16 such that the tines 120 are received into therecesses 86, 112 respectively defined therein. In such a manner, thescrew locating instrument 14 and the plate locating instrument 16 arecaptured by the tines 120. In particular, the portion of the outersleeve 54 of the screw locating instrument 14 located between therecesses 86, along with the portion of the body 88 of the plate locatinginstrument 16 located between the recesses 112, is captured or otherwiseretained in a channel 122 defined between the tines 120 (see FIG. 17).

It should be appreciated that when the tines 120 of the alignmentinstrument 18 are positioned in the recesses 86, 112 of the instruments14, 16, respectively, the instruments 14, 16 are positioned in adesired, predetermined position relative to one another. Specifically,the configuration of the instruments 14, 16 (e.g., the dimensionaldesign thereof) is predetermined such that when captured by the tines120 in the manner described above, the implantable components securedthereto (i.e., the lag screw assembly 22 and the bone plate 12) arepositioned in a desired position relative to one another. As will bedescribed below in greater detail, such alignment of the implantedcomponents allows for in vivo assembly of an implantable orthopaedicassembly.

Referring now to FIG. 6 and 7, there is shown the screw targetinginstrument 20 in greater detail. The screw targeting instrument 20includes a body 124 having a number of guide holes 126 defined therein.As will be discussed below in greater detail, bone screws, along withthe instruments utilized for the implantation thereof, are advancedthrough the guide holes 126. As shown in FIG. 18, the screw targetinginstrument 20 is configured such that the guide holes 126 align with theholes 42 of the bone plate 12 when the screw targeting instrument 20 andthe bone plate 12 are secured to the plate locating instrument 16.

The screw targeting instrument 20 also has a slot 128 defined therein.The inner sleeve 102 (and hence the shaft 92) of the plate locatinginstrument 16 is received into the slot 128 during securement of thescrew targeting instrument 20 to the plate locating instrument 16.Moreover, the body 124 of the screw targeting instrument 20 has a pairof cam surfaces 130 defined therein. During securement of the screwtargeting instrument 20 to the plate locating instrument 16, the camsurfaces 130 urge the knob 104 upwardly. Specifically, as the innersleeve 102 of the plate locating instrument 16 is received into the slot128 of the screw targeting instrument 20, the cam surfaces 130 engagethe lower surface 132 of the knob 104 (see FIGS. 3 and 4) thereby urgingthe knob 104 upwardly. Such upward movement of the knob 104 compressesthe spring 106 thereby causing lower surface 132 of the knob 104 to bereceived into the slot 128 while also causing a shoulder surface 133 ofthe knob 104 to be biased downwardly onto the upper surface 134 of thebody 124 of the screw targeting instrument 20. The exertion of such aspring bias on the screw targeting instrument 20 facilitates securementof the instruments 16, 20 to one another.

In operation, the surgical instrument assembly 10 may be utilized topercutaneously implant an orthopaedic assembly into the body of apatient. In the exemplary embodiment described herein, the surgicalinstrument assembly 10 may be utilized to implant and secure the boneplate 12 and the associated screws to the patient's femur 200. Aprocedure utilizing the surgical instrument assembly 10 is shown inFIGS. 12-18. Prior to performance of the surgical procedure, a number ofplanning steps are performed. For instance, the surgeon may review anumber of anteroposterior and lateral radiographs of the patient'spelvis and affected femur 200 in order to assess, amongst other things,fracture stability, bone quality, neck-shaft angle of the femur, alongwith the gathering of an estimate of the length of the bone plate 12that is to be utilized. A number of surgical templates (not shown) maybe utilized to preoperatively plan such items as plate angle, platelength, and length of the lag screw (both length of the barrel and thescrew itself).

As shown in FIG. 12, a small skin incision 202 is cut distally a totalof 3-4 centimeters from the flare of the greater trochanter. Theincision 202 extends through the skin along with the subcutaneous tissuethereunder to the fascia lata (not shown). The fascia lata is thenincised longitudinally in line with its fibers thereby exposing thevastus lateralis muscle (not shown). Thereafter, the vastus lateralismuscle is retracted anteriorly to expose the lateral aspect of the femur200. Once the femur 200 is exposed, a guide pin 204 is inserted into thecenter of the femoral head 206. Note that an image intensifier (notshown) may be used by the surgeon in order to ensure the guide pin 204is centered in both the anterior/posterior direction and themedial/lateral direction. Thereafter, a number of cannulated reamers andtaps (not shown) are utilized to form a tapped hole 208 in the femur 200which corresponds to the lag screw assembly 22 to be utilized.

As shown in FIG. 13, once the tapped hole 208 has been formed in thefemur 200, the lag screw assembly 22 is implanted and secured to thefemur 200. Specifically, the screw locating instrument 14 is firstsecured to the lag screw assembly 22 and thereafter implanted into thebody of the patient. To secure the screw locating instrument 14 to thelag screw assembly 22, the surgeon first rotates the knob 64 (and hencethe rod 60) of the instrument 14 in a direction which causes the threads68 of the rod 60 to threadingly engage the threads 70 of the sleeve 54in a manner which retracts or otherwise urges the beveled tip 66inwardly in a direction toward the sleeve 54. Such inward movement ofthe beveled tip 66 causes the cam surface 74 of the tip 66 to be urgedinto contact with the cam surfaces 76 of the locking arms 50 therebyovercoming the bias of the springs 58 so as to urge the locking arms 50outwardly in a direction away from one another.

With the locking arms 50 positioned in such an extended position awayfrom one another, the surgeon advances the instrument 14 in a mannerwhich allows the barbs 52 of the locking arms 50 to be slipped behindthe flange 36 of the lag screw assembly 22. Thereafter, the surgeonrotates the knob 64 (and hence the rod 60) of the instrument 14 in adirection which causes the threads 68 of the rod 60 to threadinglyengage the threads 70 of the sleeve 54 in a manner which extends orotherwise urges the beveled tip 66 outwardly in a direction away fromthe sleeve 54. Such outward movement of the beveled tip 66 causes thecam surface 74 of the tip 66 to be spaced apart from the cam surface 76of each of the locking arms 50 thereby allowing the springs 58 to urgethe locking arms 50 inwardly toward one another. Such outward movementof the beveled tip 66 also causes the conically-shaped outer surface 80thereof to be advanced into contact with the upper surface 82 of theflange 36 of the lag screw assembly 22. Such inward movement of thelocking arms 50 toward one another, along with the force exerted on theupper surface 82 of the flange 36 by the beveled tip 66, causes thebarbs 52 to engage or otherwise be urged into contact the backside ofthe flange 36 thereby securing the screw locating instrument 14 to thelag screw assembly 22, as shown in FIG. 14.

Once the screw locating instrument 14 has been secured to the lag screwassembly 22, the lag screw assembly may be implanted in the body of thepatient. The guide pin 204 is used during such implantation of the lagscrew assembly 22. Specifically, the shaft 28 of the screw 26 of the lagscrew assembly 22 is cannulated and, as a result, is advanced along theshaft of the guide pin 204. In such a manner, the lag screw assembly 22,with the screw locating instrument 14 secured thereto, is advanced alongthe guide pin 204 through the incision 202 and through the underlyingtissue to a location in which to the threads 30 of the screw 26 areadvanced into the tapped hole 208 formed in the femur 200. A cannulateddriver 210 is advanced along the guide pin 204 to assist in theimplantation of the lag screw assembly 22, and may thereafter beutilized to drive the screw 26 of the lag screw assembly 22 into thefemur 200 to a position in which the threads 30 of the screw 26 arecentralized in the femoral head 206. Image intensification may beutilized to ensure proper location of the lag screw assembly 22. Oncethe lag screw assembly 22 has been fully seated in the femur 200, theguide pin 204 is removed from the femur 200.

As shown in FIG. 14, when the lag screw assembly 22 is implanted in sucha manner, a portion of the screw locating instrument 14 extends out ofthe body of the patient through the incision 202. In a specificexemplary embodiment, the alignment recesses 86 are defined in theportion of the outer sleeve 54 of the screw locating instrument 14 whichextends out of the body of the patient.

The surgeon may then implant the bone plate 12 into the body of thepatient. To do so, the surgeon secures the bone plate 12 that is to beimplanted to the plate locating instrument 16. Specifically, the surgeonpulls upwardly on the knob 104 of the instrument 16 in order to positionthe threads 94 of the rod 92 into the recess 96 of the housing 88. Withthe threads 94 positioned in the recess 96, the surgeon advances theinstrument 16 into contact with the upper surface of the bone plate 12such that the keying tab 98 of the instrument 16 is positioned in theslot 40 of the bone plate 12. Thereafter, the surgeon rotates the knob104 thereby causing the threads 94 of the rod 92 to threadingly engagethe threads 46 defined in the bone plate 12 thereby securing the platelocating instrument 16 to the bone plate 12.

Once the instrument 16 is secured to the bone plate 12 in such a manner,the surgeon may implant the plate 12 into the body. Specifically, asshown in phantom in FIGS. 15 and 16, the surgeon advances the roundedend of the bone plate 12 is advanced through the incision 202 and theunderlying tissue to a point in which the tip of the rounded end of thebone plate 12 contacts the lateral aspect of the patient's femur 200.The surgeon then manipulates the instrument 16 such the tip of therounded end of the bone plate 12 is advanced distally along the shaft ofthe femur 200 (i.e., under the vastus lateralis). It should beappreciated that the shaft of the femur 200 functions as a guide for thesurgeon during such distal advancement of the bone plate 12. As shown inFIG. 16, the bone plate 12 is advanced to a position in which theslotted end thereof is positioned in a location which is slightly distalto the flange 36 of the lag screw assembly 22. Moreover, as shown inFIG. 16, when the bone plate 12 is implanted in such a manner, a portionof the plate locating instrument 16 extends out of the body of thepatient through the incision 202. In a specific exemplary embodiment,the alignment recesses 112 are defined in the portion of the housing 88of the plate locating instrument 16 which extends out of the body of thepatient.

Once the bone plate 12 has been implanted in such a manner, the surgeonmay secure the bone plate 12 and the lag screw assembly 22 to oneanother. In order to do so, the surgeon may utilize the alignmentinstrument 18. Specifically, the alignment instrument 18 may be advancedinto contact with both instruments 14, 16 in order to position theinstruments 14, 16 (and hence the components secured thereto) in apredetermined position relative to one another.

In the specific exemplary embodiment described herein, the surgeongrasps the handle 116 of the fork-shaped alignment instrument 18 andadvances the tines 120 thereof into cooperation with the alignmentfeatures 84, 110 of the screw locating instrument 14 and the platelocating instrument 16, respectively. Specifically, the alignmentinstrument 18 is advanced by the surgeon into contact with the screwlocating instrument 14 and the plate locating instrument 16 such thatthe tines 120 are received into the recesses 86, 112, respectively. Insuch a manner, the portion of the outer sleeve 54 of the screw locatinginstrument 14 located between the recesses 86, along with the portion ofthe body 88 of the plate locating instrument 16 located between therecesses 112, is captured or otherwise retained in the channel 122defined between the tines 120 (see FIG. 17).

As described above, when the tines 120 of the alignment instrument 18are positioned in the recesses 86, 112 of the instruments 14, 16,respectively, the instruments 14, 16 are positioned in a desired,predetermined position relative to one another. Specifically, theconfiguration of the instruments 14, 16 (e.g., the dimensional designthereof) is predetermined such that when captured by the tines 120 inthe manner described above, the implantable components secured thereto(i.e., the lag screw assembly 22 and the bone plate 12) are positionedin a desired position relative to one another.

In the specific exemplary embodiment described herein, capturing theinstruments 14, 16 with the tines 120 causes the channel 44 of the boneplate 12 to be aligned with the distal edge of the flange 36 of the lagscrew assembly 22. As the two instruments 14, 16 are advanced toward oneanother within the tines 120 of the alignment instrument 18, the distaledge of the flange 36 is received into the channel 44 of the bone plate12.

Once a portion of the distal edge of the flange 36 has been receivedinto the channel 44 of the bone plate 12, the alignment instrument 18 isremoved from the instruments 14, 16. Specifically, the alignmentinstrument 18 is moved by the surgeon in a manner which causes the tines120 to be removed from the recesses 86, 112 of the instruments 14, 16,respectively.

Thereafter, the screw locating instrument 14 may be detached from thelag screw assembly 22. Specifically, the surgeon rotates the knob 64(and hence the rod 60) of the instrument 14 in a direction which causesthe threads 68 of the rod 60 to threadingly engage the threads 70 of thesleeve 54 in a manner which retracts or otherwise urges the beveled tip66 inwardly in a direction toward the sleeve 54. Such inward movement ofthe beveled tip 66 causes the cam surface 74 of the tip 66 to be urgedinto contact with the cam surfaces 76 of the locking arms 50 therebyovercoming the bias of the springs 58 so as to urge the locking arms 50outwardly in a direction away from one another. Once the locking arms 50have been moved away from each other in such a manner, the surgeonmanipulates the screw locating instrument 14 in a manner which slips thebarbs 52 back around from the backside of the flange 36 of the lag screwassembly 22 thereby releasing the instrument 14 from the lag screwassembly 22. Once detached from the lag screw assembly 22, the surgeonadvances the screw locating instrument 14 out of the body of the patientthrough the incision 202.

Thereafter, the surgeon urges or otherwise moves the plate locatinginstrument 16 proximally in order to further advance the flange 36 ofthe lag screw assembly 22 into the channel 44 of the bone plate 12. Asshown in FIG. 18, the surgeon continues to advance the plate locatinginstrument 16 (and hence the plate 12 secured thereto) in a proximaldirection until the flange 36 is fully seated in the channel 44.

Thereafter, the surgeon may begin to insert bone screws 212 into each ofthe holes 42 of the bone plate 12. In order to do so, as shown in FIG.18, the screw targeting instrument 20 is secured to the plate locatinginstrument 16. In particular, the surgeon advances the screw targetinginstrument 20 into contact with the plate locating instrument 16 in amanner which causes the inner sleeve 102 of the plate locatinginstrument 16 to be received into the slot 128 of the screw targetinginstrument 20. During such advancement of the screw targeting instrument20 into contact with the plate locating instrument 16, the cam surfaces130 of the screw targeting instrument 20 urge the knob 104 upwardly.Specifically, as the inner sleeve 102 of the plate locating instrument16 is received into the slot 128 of the screw targeting instrument 20,the cam surfaces 130 engage the lower surface 132 of the knob 104 (seealso FIGS. 3 and 4) thereby urging the knob 104 upwardly. Such upwardmovement of the knob 104 compresses the spring 106 thereby causing thelower surface 132 of the knob 104 to be advanced into the slot 128,while causing the shoulder surface 133 of the knob 104 to be biaseddownwardly onto the upper surface 134 of the body 124 of the screwtargeting instrument 20. The exertion of such a spring bias on the screwtargeting instrument 20 facilitates securement of the instruments 16, 20to one another.

As described above, the screw targeting instrument 20 is configured suchthat the guide holes 126 align with the holes 42 of the bone plate 12when the screw targeting instrument 20 and the bone plate 12 are securedto the plate locating instrument 16. Hence, as shown in FIG. 18, oncethe screw targeting instrument 20 has been secured to the plate locatinginstrument 16, the bone screws 212 are percutaneously secured to thebone plate 12. Specifically, the shaft 216 of a screw driving instrument214 is advanced through one of the guide holes 126 defined in the screwtargeting instrument 20. A number of percutaneous, self-tapping bonescrews 212 are then advanced by the driving instrument 214 through theskin and the underlying tissue via a stab incision 220 and into one ofthe holes 42 of the bone plate 12. Each of the screws 212 is driven intothe femur 200 until the head 218 engages the bone plate 12. It should beappreciated that one of the screws 212 is advanced into each of theremaining holes 42 of the bone plate 12.

Once each of the screws 212 is installed, the screw targeting device 20is detached from the plate locating instrument 16. Thereafter, thesurgeon rotates the knob 104 of the plate locating instrument 16 in adirection which causes the threads 94 of the rod 92 to threadinglydisengage the threads 46 defined in the bone plate 12. Once the threads94 of the rod 92 have disengaged the threads 46 of the bone plate 12,the surgeon manipulates the plate locating instrument 16 such that thekeying tab 98 of the instrument 16 is removed from the slot 40 of thebone plate 12 thereby detaching the plate locating instrument 16 fromthe bone plate 12. The surgeon then advances the plate locatinginstrument 16 out of the body of the patient through the incision 202.

Once the plate locating instrument 16 has been removed from thepatient's body, the surgeon completes the surgical procedure.Specifically, the surgeon utilizes routine closure techniques to closethe incision 202 along with the stab incisions 220 created during theinstallation of each of the bone screws 212.

As shown in FIGS. 19-23, a bone screw insertion assembly 222 may be usedduring the installation of the bone screws 212. The assembly 222includes a screw sleeve 224 (see FIGS. 19 and 20), a drill guide 226(see FIG. 21), a trocar 228 (see FIG. 22), and a bone drill 230 (seeFIG. 23). The screw sleeve 224 includes a cannula 232 having a centralpassage 234 defined therein. The screw sleeve 224 also includes a hollowknob 236 having a number of threads 238 defined therein.

The drill guide 226 includes a cannula 242 having a central passage 244defined therein. The drill guide 226 also includes a hollow knob 246having a number of threads 248 defined therein. The drill guide 226 issecurable to the screw sleeve 224. Specifically, the outer surface ofthe cannula 242 of the drill guide 226 has a number of threads 250defined therein which threadingly engage the threads 238 of the screwsleeve when the cannula 242 of the drill guide 226 is inserted into thecentral passage 234 of the cannula 232 of the screw sleeve 224.

The trocar 228 has an elongated obturator 252 having a distal tip 254for puncturing tissue, and a knob 256. The trocar 228 is securable tothe drill guide 226. In particular, the outer surface of the upperportion of the obturator 252 of the trocar 228 has a number of threads258 defined therein which threadingly engage the threads 248 of thedrill guide 226 when the obturator 252 of the trocar 228 is insertedinto the central passage 244 of the cannula 242 of the drill guide 226.

The assembly 222 may be used by the surgeon to facilitate properinsertion of the bone screws 212. To do so, the trocar 228 is firstsecured within the cannula 242 of the drill guide 226, which is in turnsecured within the cannula 232 of the screw sleeve 224. Thereafter, theassembled instruments (i.e., the screw sleeve 224, the drill guide 226,and the trocar 228) are advanced through one of the guide holes 126 ofthe screw targeting instrument 20 (see FIGS. 6, 7, and 18). Thereafter,the trocar 228 is utilized to penetrate through one of the stabincisions 220. Specifically, when assembled in such a manner, the tip254 of the obturator 252 extends out of both the cannula 242 of thedrill guide 226 and the cannula 232 of the screw sleeve 224 therebyallowing the tip 254 to be utilized to puncture the underlying tissue.

During advancement of the assembled instruments through the underlyingtissue, the screw sleeve 224 may be used to engage the bone plate 12 inorder to align the assembled instruments with the holes 42 of the boneplate 12. Specifically, the distal end of the cannula 232 of the screwsleeve 224 has an alignment mechanism or feature in the form of a pairof downwardly extending flanges 260 defined therein. The flanges 260 arereceived into the oval-shaped holes 42 of the bone plate 212. Duringsuch advancement of the flanges 260 into the holes 42, the flanges 260contact the sidewalls surrounding the holes 42 thereby causing thecannulae 232, 242, and hence the tip 254 of the trocar 228, to be“centered” or otherwise aligned within the holes 42 of the bone plate12.

Once the flanges 260 of the screw sleeve 224 are positioned in the holes42 of the bone plate 12, the trocar 228 may be unscrewed from the drillguide 226 and removed therefrom. Thereafter, a drilling tip 262 of thebone drill 230 is advanced through the cental passage 244 of the drillguide 226 and operated to drill a hole in the femur 200. It should beappreciated that the diameter of the bone drill 230 is approximatelyequal to the minor diameter of the bone screws 212. Once the bone drill230 has been used by the surgeon to drill a hole to the desired depth inthe femur 200, the drill 230 is removed from the drill guide 226.Thereafter, the drill guide 226 is unscrewed from the screw sleeve 224and removed therefrom.

The screw driving instrument 214 (see FIG. 18), with a bone screw 212positioned on the end thereof, is then advanced through the screw sleeve224. The screw driving instrument 214 is then operated to drive thescrew 212 into the femur 200 until the head 218 of the screw 212 engagesthe bone plate 12. It should be appreciated that during such a screwinsertion procedure, the screw sleeve 224 functions as a tissueprotector for protecting the soft tissue in the surrounding areas.

The screw sleeve 224 may then be removed from the body of the patient.Thereafter, the remaining bone screws 212 may be inserted in a similarmanner. Once done, the stab incisions 220 may be closed in the mannerdescribed above.

While the invention has been illustrated and described in detail in thedrawings and foregoing description, such an illustration and descriptionis to be considered as exemplary and not restrictive in character, itbeing understood that only the illustrative embodiments have been shownand described and that all changes and modifications that come withinthe spirit of the invention are desired to be protected.

There are a plurality of advantages of the present invention arisingfrom the various features of the orthopaedic components, instruments,and associated surgical techniques described herein. It will be notedthat alternative embodiments of each of the orthopaedic components,instruments, and associated surgical techniques of the present inventionmay not include all of the features described yet still benefit from atleast some of the advantages of such features. Those of ordinary skillin the art may readily devise their own implementations of orthopaediccomponents, instruments, and associated surgical techniques thatincorporate one or more of the features of the present invention andfall within the spirit and scope of the present invention as defined bythe appended claims.

For example, it should be appreciated that although the screw locatinginstrument 14 is herein described as being secured to the lag screwassembly 22 prior to implantation of the lag screw assembly 22, otherconfigurations and techniques are also contemplated for use in regard tothe present invention. For example, the screw locating instrument may besecured to the lag screw in vivo subsequent to implantation of the lagscrew assembly 22. Similarly, it should be appreciated that platelocating instrument 16 may also be secured to the bone plate 12 in vivosubsequent to implantation of the bone plate 12.

1. A method of percutaneously implanting a first component and a secondcomponent of an orthopaedic assembly into a body of a patient,comprising the steps of: securing a first instrument to said firstcomponent; advancing said first component into said body; advancing saidfirst instrument into said body such that a portion of said firstinstrument extends out of said body; securing a second instrument tosaid second component; advancing said second component into said body;advancing said second instrument into said body such that a portion ofsaid second instrument extends out of said body; and advancing a thirdinstrument into contact with both said first instrument and said secondinstrument so as to position said first component and said secondcomponent in a predetermined position relative to one another.
 2. Themethod of claim 1, wherein said step of securing said first instrumentto said first component is performed prior to said step of advancingsaid first component into said body.
 3. The method of claim 1, whereinsaid step of securing said first instrument to said first component isperformed subsequent to said step of advancing said first component intosaid body.
 4. The method of claim 1, wherein: said step of advancingsaid first component into said body includes the step of securing saidfirst component to a bone within said body, and said step of advancingsaid third instrument into contact with both said first instrument andsaid second instrument includes the step of moving said second componentinto contact with said first component.
 5. The method of claim 1,wherein: said first component includes a bone screw, said secondcomponent includes a bone plate, said step of advancing said firstcomponent into said body includes the step of screwing said bone screwinto a bone within said body, and said step of advancing said thirdinstrument into contact with both said first instrument and said secondinstrument includes the step of moving said bone plate into engagementwith said bone screw.
 6. The method of claim 5, wherein: said bone screwhas a flange secured thereto, said bone plate has a channel definedtherein, and said step of advancing said third instrument into contactwith both said first instrument and said second instrument includes thestep of moving said flange into said channel.
 7. The method of claim 1,wherein: said first instrument has a first recess defined therein, saidsecond instrument has a second recess defined therein, said thirdinstrument has an alignment member extending therefrom, and said step ofadvancing said third instrument into contact with both said firstinstrument and said second instrument includes the step of advancingsaid alignment member into both said first recess and said secondrecess.